Source: UNIVERSITY OF MISSOURI submitted to
NANOTECHNOLOGY AND BIOSENSORS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1010814
Grant No.
(N/A)
Project No.
MO-MSFE0007
Proposal No.
(N/A)
Multistate No.
NC-_old1194
Program Code
(N/A)
Project Start Date
Oct 1, 2016
Project End Date
Sep 30, 2021
Grant Year
(N/A)
Project Director
Lin, ME.
Recipient Organization
UNIVERSITY OF MISSOURI
(N/A)
COLUMBIA,MO 65211
Performing Department
Food Systems & Bioengineering
Non Technical Summary
There have been increasing concerns recently about chemical and biological contaminants in various foods. In addition, there is growing attention in utilizing novel nanomaterials as highly sensitive, low-cost, and reproducible substrates for nanosensor applications. The objective of this study is to develop SERS method for rapid detection of contaminants that are extracted from different types of food samples. Various SERS substrates will be developed and evaluated. This project will develop rapid, reliable, sensitive, and reproducible methods for the detection of chemical and biological contaminants in foods.
Animal Health Component
0%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
71150101000100%
Knowledge Area
711 - Ensure Food Products Free of Harmful Chemicals, Including Residues from Agricultural and Other Sources;

Subject Of Investigation
5010 - Food;

Field Of Science
1000 - Biochemistry and biophysics;
Goals / Objectives
Develop new technologies for characterizing fundamental nanoscale processes Construct and characterize self-assembled nanostructures Develop devices and systems incorporating microfabrication and nanotechnology Develop a framework for economic, environmental and health risk assessment for nanotechnologies applied to food, agriculture and biological systems
Project Methods
The aim of this study is to 1) develop a SERS method coupled with standing gold nanorod arrays or silver nanoparticles to detect pesticides in fruit juice (i.e. orange and grapefruit) and in milk; 2) develop novel methods for detection of engineered nanoparticles (silver, titanium dioxide, etc) in foods; 3) detect toxins and other biological contaminants in foods.

Progress 10/01/20 to 09/30/21

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?The target audience who will benefit from this project includes the food industry, government agencies, food scientists, students, and food professionals from academia. This project can also train motivated students to conduct research using cutting-edge nanotechnology. The results of this project will be published in peer-reviewed journals and disseminated at professional conferences, including International Association for Food Protection (IAFP), the American Chemical Society (ACS), and International Food Technologists (IFT). SERS microchip sensor features many improvements over the bench-top analytical devices. Inclusion of a filtration step in the SERS microchip platform reduces the complexity of the initial sample and improves selective detection. The broader public will benefit from this project because developing sensitive and cost-efficient SERS technologies for rapid detection of food contaminants would be a valuable tool for the US food safety inspectors and private industry, which will improve inspection by providing increased capacity for screening a larger number of foods. The results of this project will serve the consumer demand for safe and wholesome foods and increase public confidence in our food supply. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? In this study, a SERS microchip-coupled with filtration for detection of pesticides in fresh produce was established. The sensor contains two main channels, between which a filter membrane has been bonded at the inlet site. Food sample is filtered out from the unwanted parts while flowing from the upper to the lower channel. The filtrate is then mixed with nanoparticle colloid solution and analyzed by SERS in the detection zone while moving through the lower channel. Hypothetically, on-chip filtration at the sensor inlet removes interfering particulates, resulting in a more selective and accurate SERS detection of multiple analytes or mixed samples. Since real food samples usually contain different contaminants, a sensor should be able to detect multiple targets to be considered as a practicable detection technique. To address this requirement, strawberry was chosen as the food sample in this study. Four pesticides, thiabendazole (fungicide), thiram (fungicide), endosulfan (insecticide), and malathion (insecticide), which are commonly used for cultivation of strawberries were selected for this purpose. Au@Ag nanoparticles have been used as the SERS substrate in our study since their multiple SERS detection ability for pesticides has been demonstrated before. Optimum features for the design geometry, efficient mixing of filtrate and nanoparticles in the mixing zone (at the lower channel) and highly sensitive detection in detection region were determined using finite element method (FEM) and the obtained values were used for the whole analytical experiments.

Publications


    Progress 10/01/16 to 09/30/21

    Outputs
    Target Audience:The target audience who will benefit from this project includes the food industry, government agencies, food scientists, students, and food professionals from academia. This project can also train motivated students to conduct research using cutting-edge nanotechnology. The results of this project will be published in peer-reviewed journals and disseminated at professional conferences, including International Association for Food Protection (IAFP), the American Chemical Society (ACS), and International Food Technologists (IFT). Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

    Impacts
    What was accomplished under these goals? In this study, a SERS microchip-coupled with filtration for detection of pesticides in fresh produce was established. The sensor contains two main channels, between which a filter membrane has been bonded at the inlet site. Food sample is filtered out from the unwanted parts while flowing from the upper to the lower channel. The filtrate is then mixed with nanoparticle colloid solution and analyzed by SERS in the detection zone while moving through the lower channel. Hypothetically, on-chip filtration at the sensor inlet removes interfering particulates, resulting in a more selective and accurate SERS detection of multiple analytes or mixed samples. Since real food samples usually contain different contaminants, a sensor should be able to detect multiple targets to be considered as a practicable detection technique. To address this requirement, strawberry was chosen as the food sample in this study. Four pesticides, thiabendazole (fungicide), thiram (fungicide), endosulfan (insecticide), and malathion (insecticide), which are commonly used for cultivation of strawberries were selected for this purpose. Au@Ag nanoparticles have been used as the SERS substrate in our study since their multiple SERS detection ability for pesticides has been demonstrated before. Optimum features for the design geometry, efficient mixing of filtrate and nanoparticles in the mixing zone (at the lower channel) and highly sensitive detection in detection region were determined using finite element method (FEM) and the obtained values were used for the whole analytical experiments.

    Publications


      Progress 10/01/19 to 09/30/20

      Outputs
      Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?The target audience who will benefit from this project includes the food industry, government agencies, food scientists, students, and food professionals from academia. This project can also train motivated students to conduct research using cutting-edge nanotechnology. The results of this project will be published in peer-reviewed journals and disseminated at professional conferences, including International Food Technologists (IFT), International Association for Food Protection (IAFP), and American Chemical Society (ACS). The synthesized nanocomposite can be readily used for real food analysis with reproducible SERS measurements and with little matrix interference. Satisfactory results indicate the capacity of this nanocomposite for detection, identification, and quantification of pesticides by SERS. The broader public will benefit from this project because developing sensitive and cost-efficient SERS technologies for rapid detection of food contaminants would be a valuable tool for the US food safety inspectors and private industry, which will improve inspection by providing increased capacity for screening a larger number of foods. The results of this project will serve the consumer demand for safe and wholesome foods and increase public confidence in our food supply. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

      Impacts
      What was accomplished under these goals? SERS performance is highly dependent on the SERS-active substrate. Conventionally, roughened noble metal nanoparticles having been widely used as the SERS substrates, such as gold nanoparticles (Au NPs) or silver nanoparticles (Ag NPs). However, single-element nanoparticles (Au or Ag NPs) have restricted plasmonic absorptions. Tunable LSPR and richer plasmonic modes can be obtained by combining Au and Ag in a bimetallic nanoparticle. It is believed that Ag coating of Au NPs can continuously enhance Raman intensities. In other words, gold-silver core-shell nanoparticles (Au@Ag NPs) take advantage of high SERS activity of Ag NPs and homogeneity and stability of Au NPs. Additionally, LSPR of a bimetallic nanoparticle can be tuned by varying the core size or the thickness of the coating layer. These features make Au@Ag NPs an attractive candidate as the SERS substrate. In addition, cellulose, as a SERS substrate platform, has gained favor owing to its abundancy, inexpensiveness, flexibility, ease of functionalization, and biodegradability. High sensitivity of these substrates is a result of natural wrinkles and high porosity of cellulose, leading to a large area for the creation of so-called plasmonic "hotspots". Having no or very little interference adds another advantage to cellulose-based nanocomposites as the SERS substrates. This study aimed at the synthesis of nanofibrillar cellulose (NFC)/Au@Ag NP nanocomposite. Characterization of both Au@Ag NPs and NFC/Au@Ag NP nanocomposite was conducted to indicate the successful fabrication of the SERS substrate. The new substrate was utilized to detect two widely used pesticides (thiram, a dithiocarbamate fungicide, and paraquat, a bipyridyl herbicide) either individually or as a mixture in lettuce samples. The as-prepared NFC/Au@Ag NP nanocomposite was used in SERS analysis, which was analyzed by multivariate statistical tools.

      Publications


        Progress 10/01/18 to 09/30/19

        Outputs
        Target Audience:Audiences include food scientists, students, professionals from academia, the food industry, and government. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?We provided training opportunities for two MS and three Ph.D. students who worked on this project. How have the results been disseminated to communities of interest?We have disseminated our results/data at the professional conferences including IFT, IAFP, and ACS. What do you plan to do during the next reporting period to accomplish the goals?We will continue to develop new technologies for characterizing fundamental nanoscale processes;construct and characterize self-assembled nanostructures; develop devices and systems incorporating microfabrication and nanotechnology; develop a framework for economic, environmental and health risk assessment for nanotechnologies applied to food, agriculture and biological systems. More specifically,we will keep working on developing SERS methods coupled with nanosubstrates for detecting chemical contaminants in foods, and developing novel nanostructures using inorganic materials for food safety applications.

        Impacts
        What was accomplished under these goals? During the reporting period, experiments were carried out for facile synthesis of cellulose nanofiber nanocomposite as a SERS substrate for detection of thiram in juice.There has been growing interest in the use of nanocellulose-based substrate for surface-enhanced Raman spectroscopy (SERS) applications.This study aimed touse cellulose nanofibers (CNF) to develop novel CNF-based nanocomposite as a SERS substrate.CNF were cationized with ammonium ions and then interacted with citrate-stabilized gold nanoparticles (AuNPs) via electrostatic attraction to form uniform nanocomposites. The CNF-based nanostructures were loaded with AuNPs that were firmly adhered on the CNF surfaces, providing a three-dimensional plasmonic SERS platform. A Raman-active probe molecule, 4-aminothiophenol, was selected to evaluate the sensitivity and reproducibility of CNF-based SERS substrate. The intensity of SERS spectra obtained from CNF/AuNP nanocomposite was 20 times higher than that from the filter paper/AuNP substrate. The SERS intensity map demonstrates good uniformity of the CNF/AuNP substrate. CNF/AuNP nanocomposites were used in rapid detection of thiram in apple juice by SERS and a limit of detection of 52 ppbof thiram was achieved. These results demonstrate that CNF/AuNP nanocomposite can be used for rapid and sensitive detection of pesticides in food products. In addition, another study was conducted to develop SERS method for rapid detection of pesticides that were extracted from different types of food samples (fruit juice and milk). A new SERS substrate was prepared by assembling gold nanorods into standing arrays on a gold-coated silicon slide. The standing nanorod arrays were neatly arranged, and were able to generate strong electromagnetic field in SERS measurement. The as-prepared SERS substrate was utilized to detect carbaryl in acetonitrile-water solution, fruits juice (orange and grapefruit), and milk. The results show that the concentrations of carbaryl spiked in fruit juice and milk were linearly correlated with the concentrations predicted by the partial least squares (PLS) models with r value of 0.91, 0.88, and 0.95 for orange juice, grapefruit juice, and milk, respectively. The SERS method was able to detect carbaryl that was extracted from fruits juice and milk samples at 50 ppb level. The detection limits of carbaryl were 509, 617, and 319 ppb in orange juice, grapefruit juice, and milk, respectively. All detection limits are below the Maximum Residue Limits that were set by the U.S. EPA. Moreover, satisfactory recoveries (82 to 97.5%) were accomplished for food samples using this method. These results demonstrate that SERS coupled with the standing gold nanorod array substrates is a rapid, reliable, sensitive, and reproducible method for the detection of pesticide residues in foods.

        Publications

        • Type: Journal Articles Status: Published Year Published: 2019 Citation: Asgari, S., Saberi, A.H., McClements, D.J., Lin, M. 2019. Microemulsions as nanoreactors for synthesis of biopolymer nanoparticles. Trends in Food Science & Technology, 86, 118-130.
        • Type: Journal Articles Status: Published Year Published: 2019 Citation: Sun, L., Yu, Z., Lin, M. 2019. Synthesis of polyhedral gold nanostars as surface-enhanced Raman spectroscopy substrates for measurement of thiram in peach juice. Analyst, 144, 4820-4825.
        • Type: Journal Articles Status: Published Year Published: 2019 Citation: Yu, Z., Dhital, R., Wang, W., Sun, L., Zeng, W., Mustapha, A., Lin, M. 2019. Development of multifunctional nanocomposites containing cellulose nanofibrils and soy proteins as food packaging material. Food Packaging and Shelf Life, 21, 100366.
        • Type: Journal Articles Status: Published Year Published: 2019 Citation: Yu, Z., Wang, W., Kong, F., Lin, M., Mustapha, A. 2019. Cellulose nanofibril/silver nanoparticle composite as an active food packaging system and its toxicity to human colon cells. International Journal of Biological Macromolecules. 129, 887-894.
        • Type: Journal Articles Status: Published Year Published: 2019 Citation: Yu, Z., Wang, W., Dhital, R., Kong, F., Mustapha, M., Lin, M. 2019. Antimicrobial effect and toxicity of cellulose nanofibril/silver nanoparticle nanocomposite prepared by an ultraviolet irradiation method. Colloids Surf. B. 180, 212-220.
        • Type: Journal Articles Status: Published Year Published: 2019 Citation: J. W. Su, W. Gao, K. Trinh, S. M. Kenderes, E. T. Pulatsu, C. Zhang, A. G. Whittington, M. Lin, and J. Lin. 4D printing of polyurethane paint based composites. International Journal of Smart and Nano Materials 10, 3, 237-248 (2019).
        • Type: Journal Articles Status: Published Year Published: 2018 Citation: Tian, K., Chen, X., Luan B., Singh, P., Yang, Z., Gates, K.S., Lin, M., Mustapha, A., Gu, L.-Q. 2018. Single LNA-enhanced genetic discrimination of foodborne pathogenic serotype in a nanopore. ACS nano. 12, 4194-4205.
        • Type: Journal Articles Status: Published Year Published: 2018 Citation: Xiong, Z., Lin, M., Lin, H., Huang, M. 2018. Facile synthesis of cellulose nanofiber nanocomposite as a SERS substrate for detection of thiram in juice. Carbohydr. Polym. 189, 79-86.
        • Type: Journal Articles Status: Published Year Published: 2018 Citation: Alsammarraie, A.K., Wang, W., Zhou, P., Mustapha, A., Lin, M. 2018. Green synthesis of silver nanoparticles using turmeric extracts and investigation of their antibacterial activities. Colloids Surf. B. 171, 398-405.


        Progress 10/01/17 to 09/30/18

        Outputs
        Target Audience:Target audiences include faculty and students in academia, food scientists the food industry, the government agencies, and consumers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?We provided training opportunities for two MS and two Ph.D. students who worked on this project.? How have the results been disseminated to communities of interest?We have disseminated our results/data at the professional conferences including IFT, IAFP, and ACS. What do you plan to do during the next reporting period to accomplish the goals?We willcontinueto develop new technologies for characterizing fundamental nanoscale processes; construct and characterize self-assembled nanostructures; and develop devices and systems using nanotechnology.

        Impacts
        What was accomplished under these goals? In the reporting period of time, our study was todevelop nanofibrillated cellulose (NFC)-based substrate for rapid detection of melamine in milk by surface-enhanced Raman spectroscopy (SERS). NFC served as a highly porous platform to load with gold nanoparticles (AuNPs), which can be used as a flexible SERS substrate with nanoscale roughness to generate strong electromagnetic field in SERS measurement. The NFC/AuNP substrate was characterized by UV-vis spectroscopy and electron microscopy. Milk samples contaminated by different concentrations of melamine were measured by SERS coupled with NFC/AuNP substrate. The spectral data analysis was conducted by multivariate statistical analysis (i.e. partial least squares (PLS)). Satisfactory PLS result for quantification of melamine in milk was obtained (R = 0.9464). The detection limit for melamine extracted from liquid milk by SERS is 1 ppm, which meets the World Health Organization's requirement of melamine in liquid milk. These results demonstrate that NFC/AuNP substrate has improved homogeneity and can be used in SERS analysis to for food safety applications. Our another study investigated a nanopore-based single-molecule approach, facilitated the locked nucleic acid (LNA) technique, to accurately determine this SNP for genetic discrimination of the O157:H7 serotype. Rapid and accurate detection of foodborne pathogens is crucial in safety regulation of food products and proper diagnosis of related diseases.Shiga toxin producingEscherichia coli(STEC)O157:H7 is a deadly pathogenicserotype. Genetically, this pathogen can be distinguished from all non- O157:H7 serotypes based on the single nucleotide polymorphism (SNP) in theuidA gene (uidA +93). Remarkably, unlike traditional LNA applications that need incorporation and optimization of multiple LNA nucleotides, our results demonstrate that in the nanopore system a single LNA introduced in the probe is sufficient to enhance the SNP discrimination capability by 10-fold, allowing the detection of the O157:H7 DNA at 1% when contaminated with large amount of the non-O157:H7 DNA. The mechanistic study suggests that such significant improvement is due to the single LNA effect on both stabilizing the fully matched base-pair and destabilizing the mismatched base-pair. These results demonstrate that this sensitive method coupled with simplified, low cost, easy-to-operate LNA design, can be generalized and applied in foodborne detection and other fields, such as identification of genomic mutations and nucleotide polymorphisms.

        Publications

        • Type: Journal Articles Status: Published Year Published: 2018 Citation: Xiong, Z., Lin, M., Lin, H., Huang, M. 2018. Facile synthesis of cellulose nanofiber nanocomposite as a SERS substrate for detection of thiram in juice. Carbohydr. Polym. 189, 79-86.
        • Type: Journal Articles Status: Published Year Published: 2018 Citation: Alsammarraie, A.K., Lin, M., Mustapha, A., Lin, H., Chen, X., Chen, Y., Wang, H., Huang, M. 2018. Rapid determination of thiabendazole in juice by SERS coupled with novel gold nanosubstrates. Food Chem. 259, 219-225.
        • Type: Journal Articles Status: Published Year Published: 2018 Citation: Alsammarraie, A.K., Wang, W., Zhou, P., Mustapha, A., Lin, M. 2018. Green synthesis of silver nanoparticles using turmeric extracts and investigation of their antibacterial activities. Colloids Surf. B Biointerfaces. 171, 398-405.
        • Type: Journal Articles Status: Published Year Published: 2018 Citation: Tian, K., Chen, X., Luan B., Singh, P., Yang, Z., Gates, K.S., Lin, M., Mustapha, A., Gu, L.-Q. 2018. Single LNA-enhanced genetic discrimination of foodborne pathogenic serotype in a nanopore. ACS nano. 12, 4194-4205.


        Progress 10/01/16 to 09/30/17

        Outputs
        Target Audience:The target audiences include people from the food industry, academia (faculty and students, etc), the science community, and the government agencies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided training for two doctoral students and two Master's students. How have the results been disseminated to communities of interest?We have disseminated the results to the industry and scientific communities at professional conferences such as IFT, ACS, and IAFP. What do you plan to do during the next reporting period to accomplish the goals?We will continue to develop new technologies for characterizing fundamental nanoscale processes; construct and characterize self-assembled nanostructures; develop devices and systems incorporating microfabrication and nanotechnology; and develop a framework for economic, environmental and health risk assessment for nanotechnologies applied to food, agriculture and biological systems.

        Impacts
        What was accomplished under these goals? In this project, we used new technologies to develop nanostructures and nanosubstrates for surface-enhanced Raman spectroscopy (SERS) applications.This study aimed to use cellulose nanofibers (CNF) to develop novel CNF-based nanocomposite as a SERS substrate. CNF were cationized with ammonium ions and then interacted with citrate-stabilized gold nanoparticles (AuNPs) via electrostatic attraction to form uniform nanocomposites. The CNF-based nanostructures were loaded with AuNPs that were firmly adhered on the CNF surfaces, providing a three-dimensional plasmonic SERS platform. A Raman-active probe molecule, 4-aminothiophenol, was selected to evaluate the sensitivity and reproducibility of CNF-based SERS substrate. The intensity of SERS spectra obtained from CNF/AuNP nanocomposite was 20 times higher than that from the filter paper/AuNP substrate. The SERS intensity map demonstrates good uniformity of the CNF/AuNP substrate. CNF/AuNP nanocomposites were used in rapid detection of thiram in apple juice by SERS and a limit of detection of 52 ppb of thiram was achieved. These results demonstrate that CNF/AuNP nanocomposite can be used for rapid and sensitive detection of pesticides in food products. We also developed CNF-based substrate for rapid detection of melamine in milk by SERS. CNF served as a highly porous platform to load with gold nanoparticles (AuNPs), which can be used as a flexible SERS substrate with nanoscale roughness to generate strong electromagnetic field in SERS measurement. The CNF/AuNP substrate was characterized by UV-vis spectroscopy and electron microscopy. Milk samples contaminated by different concentrations of melamine were measured by SERS coupled with CNF/AuNP substrate. The spectral data analysis was conducted by multivariate statistical analysis (i.e. partial least squares (PLS)). Satisfactory PLS result for quantification of melamine in milk was obtained (R = 0.9464). The detection limit for melamine extracted from liquid milk by SERS is 1 ppm, which meets the World Health Organization's requirement of melamine in liquid milk. These results demonstrate that CNF/AuNP substrate has improved homogeneity and can be used in SERS analysis to for food safety applications.

        Publications

        • Type: Journal Articles Status: Published Year Published: 2017 Citation: Liou, P., Nayigiziki, F. X., Kong, F., Mustapha, A., Lin, M. 2017. Cellulose nanofibers coated with silver nanoparticles as a SERS platform for detection of pesticides in apples. Carbohydr. Polym. 157, 643-650.
        • Type: Journal Articles Status: Published Year Published: 2017 Citation: Alsammarraie, F.K., Lin, M.* 2017. Using standing gold nanorod arrays as SERS substrates for detection of carbaryl residues in fruit juice and milk. J. Agric. Food Chem. 65(3), 666-674.
        • Type: Journal Articles Status: Submitted Year Published: 2017 Citation: Nguyen, T., Vardhanabhuti, B., Lin, M., Azlin Mustapha. 2017. Antibacterial properties of selenium nanoparticles and their toxicity to Caco-2 cells. Food Control. 77, 17-24.
        • Type: Journal Articles Status: Published Year Published: 2017 Citation: Xiong, Z., Chen, X., Liou, P., Lin, M. 2017. Development of nanofibrillated cellulose coated with gold nanoparticles for measurement of melamine by SERS. Cellulose. 24, 2801-2811.
        • Type: Journal Articles Status: Published Year Published: 2017 Citation: Chen, X., Nguyen, T., Gu, L., Lin, M. 2017. Use of standing gold nanorods for detection of malachite green and crystal violet in fish by SERS. J. Food Sci. 82(7), 1640-1646.
        • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Alsammarraie, F.K., Lin, M. Using standing gold nanorod arrays as SERS substrates for detection of carbaryl residues in fruit juice and milk. 2017 IFT Annual Meeting. June 25-28, Las Vegas, NV.
        • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Lin, M., Alsammarraie, F., Liou, P. Use of gold nanorod arrays and cellulose nanocomposite as SERS substrates for detection of pesticide residues in foods. 2017 TechConnect World Innovation Conference. May 14-17, 2017.
        • Type: Journal Articles Status: Published Year Published: 2016 Citation: Nguyen, T., Zhou, P., Mustapha, M., Lin, M. 2016. Detection of silver nanoparticles in consumer products by surface-enhanced Raman spectroscopy. Analyst. 141, 5382-5389.